Re: [Drakelist] R4B Transformer temp
The transformer and nearby audio output tube do heat up that corner seriously. Many of us prolong life with a small fan. I just take a computer fan (larger diameter preferred), put some rubber feet on it, and then simply place it on the top cover of my R4B over that area. The fan is oriented so that the hot air is drawn upward. I run the fan on reduced voltage so it is not heard. It's a simple non-invasive trick and makes a big difference in temp. Dennis AE6C On 6/17/12, Eugene Balinski euge...@nni.com wrote: All, Was poking around the operating table the other day when my hand happened to brush across the top of my R4B. I noticed that even through the top cover, the transformer seemed very warm - virtually hot. I will assume that this is not normal (never noticed it before) and is indicative of a problem ? If this is an issue, any ideas on where to look ? Leaky cap in PS ? Audio and performance seem nominal 73 and thanks, Gene K1NR - Web mail provided by NuNet, Inc. The Premier National provider. http://www.nni.com/ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4B Transformer temp
euge...@nni.com writes: R4B. I noticed that even the transformer seemed very warm - virtually hot. Probably the tube just to the right of it, a small fan on top of the case helps a lot. Carl WD8NHK that's what I do with my R4___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4B Transformer temp
It's normal for the R-4B power transformer to run hot. And to Carl's point, the audio tube, running class A near the transformer adds even more heat. I really dislike cabinet heat and rather than use a fan, I went to the extreme last year and made several circuit conversions. The first phase involved replacing the power transformer with the type found in the R-4C, then converting all 12.6v tubes to their 6.3V equivalents. This was followed by the installation of the Sherwood PS-4 upgrade to further reduce heat by eliminating power-hungry resistive dividers. The last phase involved complete removal and replacement of the class A audio stage with a discrete, audiophile-grade Class AB push-pull audio board. After the mods, the R-4B is cool to the touch, like a Sherwood modified R-4C. This was an extensive experimental exercise and I don't recommend it as a casual upgrade. Probably with even a modest amount of air flow, the cabinet will run significantly cooler. Paul, W9AC - Original Message - From: gypsym...@aol.com To: euge...@nni.com ; Drakelist@zerobeat.net Sent: Monday, June 18, 2012 7:09 AM Subject: Re: [Drakelist] R4B Transformer temp euge...@nni.com writes: R4B. I noticed that even the transformer seemed very warm - virtually hot. Probably the tube just to the right of it, a small fan on top of the case helps a lot. Carl WD8NHK that's what I do with my R4 -- ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Drake R4C filters for sale
Fellow Drake enthusiasts, Have a couple of Drake filters for sale that can be plugged into the sockets on the rear panel of the receiver. 1. FL-4000 which is a 4 kc filter used for AM, shortwave listening, or full fidelity SSB. $75 plus shipping. 2. CF-2K/16 which is a 16 pole, narrow SSB filter made by Sherwood Engineering. $100 plus shipping. Can only ship these to continental US only. Payment must be via USPS money order or PayPal. Thanks for reading the posting. 73, Evan, K9SQG ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
